question for ml, page-18

TR

The corridor to build a 1m dia water pipeline I worked on was as narrow as 10m in places and nowhere needed to be wider than about 20m ... this pipeline was tyically 2-4 m deep in mostly difficult low strength alluvium.

I did some investigations on the Darwin to Alice Springs gas pipeline in the mid 80's, but the gas pipeline I mentioned has yet to be built. It is a 27 km long feeder to a proposed gas fired peaking power station. Depending on whether or not that line is to be used for pressurised storage, the expected dia is 300-600mm ... this pipeline will be buried in the 1.5-2.0m depth range, as I also understand are most gas pipelines.

Creek crossings can be piled structures using the pipeline as one of the structural elements. They can also be trenched if conditions are dry at the time of construction. In some cases they can be placed by underboring, for which there is no surface disturbance.

The water pipeline I mentioned was constructed at depth beneath a major river crossing by underboring ... amazing technology ... and generally not even landholders notice its happening.

I'm just giving you some feedback from my direct experience ... a gas pipeline is nothing like the scale and tale of woe you describe.

Cheers
Dex